Pupils are to be allocated a unique "Scottish Candidate Number" (SCN) when they arrive in primary 1 in a child protection move by the Scottish Executive.
It follows the case of the murdered Inverness five-year-old Danielle Reid, whose mother was able to withdraw her from school in the city by simply informing staff that the family was moving to Manchester.
Previously, the pupil identifier was allocated in secondary school, usually in S3, as a candidate number for exam presentation. Now a programme is being rolled out across Scotland to allocate it to all primary and special school pupils.
The unique pupil ID number will, it is hoped, play a key role in developing the school-to-school transfer system, currently being created to improve record-sharing and the monitoring of progress when pupils change school.
It will particularly benefit the Children Missing Education (CME) project launched last year to help locate children who have disappeared from the education system. Since its launch in August, the project has traced 114 children referred to them by the education authorities.